Comme prévu, Porsche présente la seconde génération du Cayman GT4, à Daytona aux essais IMSA. Après 421 exemplaires produits (à ce jour), le nouveau 718 Cayman GT4 Clubsport (type 982) est proposé en deux versions : Trackday et Compétition. Au menu, le même mécanique flat 6 atmo 3.8L qui développe 425 ch soit 40 de plus et 425 Nm soit 5 de plus, une masse de 1,32T soit 20 kg de moins, suspension (avant) et freins de 911 GT3 Cup, de l’aéro assorti avec de la “fibre composite naturelle” pour plus d’écologique (moins polluant que la fibre de carbone).
Sérieuse évolution
Avec le 718 Cayman et son 4 cylindres turbo, nous avions peur de perdre un “vrai” moteur : le flat 6 3.8L atmo. Il n’en est rien, Porsche a conservé le même bloc – même si nous attendions une évolution à 4.0L – développant 425 ch (313 kW à 7500 tr/min) et 425 Nm (à 6600 tr/min), avec un régime maxi à 7800 tr/min. Le gain est de 40 ch (+100 tr/min) et 5 Nm (+600 tr/min), la zone rouge baissant de 100 tr/min (Taux de compression 12,5:1). Le tout est associé à une boîte 6 rapports à double embrayage qui propulse la voiture aux roues arrières (pas de transmission intégrale).
La suspension avant est empruntée à la 911 GT3 Cup et un système de freinage “Racing” composé de disques de 380 mm complète la dotation spécifique mécanique. L’aérodynamique a été modifié pour fournir plus d’appui et la carrosserie adopte des fibres composites naturelles (fibres organiques) issues de déchets agricoles (dont le lin et le chanvre), pour les portes et l’aileron. Porsche affirme que ce nouveau matériau d’avenir propose des propriétés de rigidité et de légèreté identiques à la fibre de carbone. Résultat sur la balance : 1320 kg.
Deux versions du nouveau 718 Cayman GT4 Clubsport sont disponibles : Trackday et Compétition. La première ; affichée à 134 000 euros HT ; dispose d’un pré-réglage de la suspension, des aides à la conduites tels que l’ABS, le contrôle de traction, etc… et un réservoir de 80L. La seconde ; vendue 157 000 euros HT ; opte pour des amortisseurs et une répartition de freinage réglables, un réservoir de 115L avec système air jack garantissant des ravitaillements rapides et un volant amovible issu avec la 911 GT3 R.
Disponible dès Février 2019. Fiche technique détaillée en bas de l’article (après les photos).
Fiche technique Porsche 718 Cayman GT4 Clubsport (Type 982) Concept (anglais)
• Single-seater, near-standard production-based race car, not road homologat-ed
Engine
• Aluminium six-cylinder mid-positioned boxer engine with rigid mounting
• 3,800 cc; stroke 77.5 mm, bore 102 mm
• Max. power: 313 kW (425 hp) at 7,500 rpm
• Max. rpm: 7,800 rpm
• Max. torque: 425 Nm at 6,600 rpm
• Compression ratio: 12.5:1
• Racing optimised water cooling with thermal management for engine and gearbox
• Four-valve technology with adjustable camshaft phasing and variable valve timing VarioCam Plus
• Fuel quality: Super Plus unleaded, minimum 98 octane
• Racing optimised electronic engine management (Continental SDI 9)
• Integrated dry sump lubrication
• 100-cell metal catalytic converter complying with DMSB specifications
Transmission
• Rear wheel drive
• 6-speed PDK gearbox with rigid suspension and electronic control unit opti-mised for racing
• Reinforced dual mass flywheel
• Internal pressure oil lubrication with active oil cooling
• Differential lock optimised for racing
Bodywork
• Lightweight body in aluminium-steel composite construction
• Welded-in roll cage, certified according to FIA Art. 277
• Front bonnet with quick release fasteners
• Rear hood with quick release fasteners
• Fixed rear wing with “swan neck” mount made of natural-fibre composite ma¬terials, including the sideblades, black aluminium wing supports with integrat-ed carbon fibre Gurney flap
• Driver and co-driver doors of natural-fibre composite materials
• Roof including escape hatch, certified according to FIA Art. 275a
• Recaro race bucket seat with longitudinal adjustment and padding system, ad-justable to the individual needs of the drivers (in accordance with FIA Stand¬ard 8862/2009 – the latest FIA requirements)
• Three-piston air jack system (“Competition”)
• Pre-installed mounting points for three-piston air jack system (“Trackday”)
• Provision for safety net
• FIA-certified towing loops, front and rear
• Motorsport centre console with enhanced functionality and adapted usability
• Six-point safety harness
• 115-litre FT3 safety fuel cell with “Fuel Cut Off” safety valve complying with FIA regulations (“Competition”)
• 80-litre FT3 safety fuel cell with “Fuel Cut Off” safety valve complying with FIA regulations (“Trackday”)
Suspension
Front axle:
• MacPherson suspension strut, adjustable in height, camber and track
• Forged suspension links: optimised stiffness, double shear mounting, high-performance spherical bearings
• 5-bolt wheel hubs
• Racing 3-way shock absorbers with rebound and 2-stage compression ad-justment, high and low speed (“Competition”)
• Fixed shock absorbers (“Trackday”)
• Electromechanical power steering with variable steering ratio
• Anti-roll bar, 3-hole design
Rear axle:
• MacPherson suspension strut, adjustable in height, camber and track
• Forged suspension links: optimised stiffness, double shear mounting, high-performance spherical bearings
• 5-bolt wheel hubs
• Racing 3-way shock absorbers with rebound and 2-stage compression ad-justment, high and low speed (“Competition”)
• Fixed shock absorbers (“Trackday”)
• Adjustable blade-type anti-roll bar
Brake system
Front axle:
• Aluminium, mono-bloc six-piston racing callipers with “Anti Knock Back” piston springs
• Steel brake discs, multi-piece, ventilated and grooved, 380 mm diameter
• Racing brake pads
• Brake balance adjustment via a balance bar system (“Competition”)
• Brake booster (“Trackday”)
Rear axle:
• Aluminium, mono-bloc four-piston racing callipers with “Anti Knock Back” pis¬ton springs
• Steel brake discs, multi-piece, ventilated and grooved, 380 mm diameter
• Racing brake pads
• Brake balance adjustment via a balance bar system (“Competition”)
• Brake booster (“Trackday”) Electrics
• COSWORTH instrument cluster ICD with integrated data logger
• Upgraded fault diagnosis with PIWIS motorsport tester
• Porsche Track Precision Race App
• Integrated lap trigger via GPS signal
• Electronic throttle system
• Lightweight lithium-ion (LiFePo) battery, 60 Ah, leak-proof, mounted in pas-senger footwell (“Competition”)
• Battery 12 V, 70 Ah (AGM), leak-proof, mounted in passenger footwell (“Trackday”)
• Emergency cut-off switch in cockpit and outside left of the windscreen
• Driving stability system PSM (Porsche Stability Management) with ABS, trac¬tion Control (TC) and Electronic Stability Control (ESC), able to be completely deactivated
• Tyre pressure monitoring system (TPMS)
• Central fire extinguishing system in accordance with FIA regulations (“Compe¬tition”)
• Handheld fire extinguisher (“Trackday”)
• Air conditioning
• Electric wing mirror adjustment
• Multifunctional CFRP motorsport steering wheel with pit speed limiter and quick release coupling (“Competition”)
• Multifunctional motorsport steering wheel with pit speed limiter (“Trackday”)
• Centre console with map switch to adjust the ABS, ESC, TC and switch be-tween preset tyre circumferences
Weight/dimensions
• Total weight: 1,320 kg
• Total length: 4,456 mm
• Total width: 1,778 mm
• Total height: 1,238 mm
• Wheelbase: 2,456 mm
Rims/Tyres
Front axle:
• One-piece light-alloy forged wheels in new weight-optimised rim design, 9J x 18 offset 28 with 5-bolt mounting
• Delivered with Michelin transportation tyres, dimension: 25/64-18
• Michelin slick/wet tyres, dimension: 25/64-18
Rear axle:
• One-piece light-alloy forged wheel in new weight-optimised rim design, 10.5J x 18.5 offset 53 with 5-bolt mounting
• Delivered with Michelin transportation tyres, dimension: 27/68-18
• Michelin slick/wet tyres, dimension: 27/68-18
Colours
• Water-based paint
• Exterior: white C9A
• Interior: white filler-coat, without lacquer
Delivery : From February 2019
Source CP Porsche
